Thomas Hobbes (1588–1679) was most famous for his political philosophy and for his view of life in “the state of nature” as “solitary, poor, nasty, brutish, and short.” But he also had ideas about cognition and memory. Hobbes believed that all our knowledge comes from our sense impressions. Memories are the residues of the initial sense impressions, somewhat like waves that continue even after the wind ceases. He noted that ideas get linked together in memory when the sense impressions first occur close in time. This concept of associative memory became the basis of behaviorism, a psychological movement that arose in the twentieth century.